Rotary internal combustion engine



Dec. 27, 1955 .H. M. PETERSEN ROTARY INTERNAL COMBUSTION ENGINE 4Sheets-Sheet 1 Filed Sept. 15, 1948 R w mm w N m V T NR [E A M E P M s MA H Dec. 27, 1955 H. M; PETERSEN ROTARY INTERNAL COMBUSTION ENGINE 4Sheets-Sheet 2 Filed Sept. 16, 1948 INVENTOR HANS m, PETERSEN ArroR eYs1955 H. M. PETERSEN ROTARY INTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 3Filed Sept. 115, 1948 INVENTOR.

HANS M. PETERSEN BY 19 770/? NE Y5 Dec. 27, 1955 H. M. PETERSEN ROTARYINTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 4 Filed Sept. 15, 1948INVENTOR. HANS M. PETERSEN BY W V M 7 ATT'OQ klFYS United States PatentQ 2,728,330 ROTARY INTERNAL COMBUSTION ENGINE Califi, assignor to Inc.,a corporation of This invention relates to rotary internal combustionengines and more particularly to that type in which the rotor issubstantially concentric with the housing.

Heretofore rotary internal combustion engines designed to produce theirown suction have generally failed to develop adequate power output, haveoperated at a low efiiciency and have been characterized by excessivewear in their moving parts. One of the objects of this invention is toprovide an engine of high horsepower output per unit weight.

Another objectof the invention is the provision of a rotary internalcombustion engine of extremely simple construction and few moving parts.

A still further object of the invention is the provision of an internalcombustion engine in which wear due to friction is minimized andautomatically compensated for without loss in efiiciency.

An additional object is the provision of a rotary internal combustionengine having a simple and effective lubrication system.

Other objects and advantages will appear in the specifications anddrawings.

In the drawings,

Fig. l is an elevation of the engine partly broken away and in section.

Fig. 2 is a cross-sectional view through the engine taken along lines 22of Fig. 1.

Fig. 3 is a perspective view of one of the vanes with one of itsseparate end portions detached from the vane but positioned in itsnormal position relative to the vane.

Fig. 4 is a longitudinal sectional view (partly in elevation) of therotor taken along lines 4-4 of Fig. 2 and showing the lubricationpassages.

Fig. 5 is a cross-sectional view of a modified form of the invention.

Fig. 6 is a partial longitudinal sectional view of the form shown inFig. 5.

The engine comprises a housing 1 closed at each end by .end plates 2(Fig. l) which are bolted to the housing by bolts 3. Disposed within thehousing is a rotor 4 mounted in journal bearings 5 which are in turnreleasably secured within the end plates by means of pins 11. Tofacilitate assembly, the end plates are preferably made in two partswhich are bolted together by means of bolts 12 and nuts 13. Bearinghousing 28 may be cast integrally with the two portions of the endplates 2, thus providing a split housing.

As best seen in Fig. 1 a plurality of slots 6 preferably four in number,extend radially and longitudinally within the rotor 4. Slidably disposedwithin slots 6 are vanes generally designated 7 which are urged radiallyoutwardly against the inner wall of housing 1 by helical springs 8.

The width of slots 6 is increased at intervals along the length of theslots as by drilling holes 9 (Fig. 4-). The axes of holes 9 are radialand preferably coincide with the longitudinal center line plane of slot6. The width of vanes 7 is correspondingly increased at in- 2,728,330Patented Dec. 27, 1955 tervals along the length of the vanes as at 10(Fig. 3). The widened portions 10 of vanes 7 register with the holes 9drilled in the rotor, thus insuring only radial movement of the vanes 7with respect to rotor 4. Holes 9 continue radially through the rotor 4and serve as guides for springs 8.

In order to effectively seal the vanes 7 with the end plates 2, Iprovide end portions 14 which coact with the major portion 17 of thevanes and which are urged longitudinally outwardly of the vanes againstthe end plates 2 by helical springs 15. The major portions of the vanes17 may be slotted along their ends as at 16 to receive extensions 18 inthe end portions 14 (Fig. 3). The end portions 14 are recessed as at 19at their inner edge to register with longitudinal extensions 20 on themajor portions 17 of the vanes 7. Thus the end portions 14 are slidablysecured to the major portion 17 of the vane and may move longitudinallyand radially but not tangentially with respect to the rotor 4. The widthof slot 16 may be increased at intervals along its length to providerecesses 21 for springs 15. Cylindrical extensions 22 may be provided onend portions 14 to register with recesses 21 and to act as keepers forsprings 15.

As best seen in Fig. 2, the inner wall ofthe housing 1 generallydesignated is concentric with the axis of the rotor and spaced asubstantial distance from the rotor for a major portion of its lengtharound the rotor as at 23. For a minor portion of its length around therotor, the wall is concentric with the axis of the rotor as at 24, butat a slight distance from the rotor 4. Between the two concentricportions the inner wall curves radially inwardly as at junctures 25 fromthe major portion to the minor portion so as to provide a gradual changein the radial velocity of the vane 7 when the rotor is rotating at aconstant angular velocity. Thus the contour of the Wall between theconcentric portions is preferably such that the vane 7 has a constantradial acceleration between the concentric portions when the rotor isrotating at a constant angular velocity. The width of vane 7 ispreferably increased as at 46 to permit cutting the outer edge to alarge radius, thereby providing smooth contact between vane 7 and innerwall of housing 65, and particularly at the sloping wall 25.

Lubricant for the engine is introduced under pressure through pipe 30and bushing 31 into the bearing housing 28 through hole 29. Hole 29 maybe drilled through housing 28 and bearing 5 and the hole sealed at oneend by plug 32. Hole 26 is drilled axially of the rotor so as tointersect perpendicularly hole 29. The rotor journal 27 extends asubstantial distance longitudinally outwardly from end plates 2 toprovide clearance for coupling the rotor to the driven shaft. For thisreason hole 26 is relatively long. To prevent air pockets within hole26, I provide a relatively long shanked plug 33 having a diameterslightly less than the diameter of hole 26 to seal the hole.

As best seen in Fig. 4, each hole 26 extends from the journal 27 intorotor 4 a slight distance and is intersected by radial holes 34preferably two in number drilled through the rotor and sealed at theperiphery of the rotor by long shanked plugs 35. To provide a conduitfor longitudinal movement of the lubricant through the rotor, relativelylarge holes 36 are drilled preferably midway between slots 6 asubstantial distance from the axis of the rotor and parallel thereto.Plugs 37 seal holes 36 and are threadedly secured therein. An effectiveseal may be insured by use of gasket 39 between plug 37 and rotor 4. Theshank of plug 37 is recessed as at 38 to .provide space for thelubricant. Hole 34 is drilled through plug 37 after the plug is inplace, thus providing a continuous conduit for the lubricant runningradially tion chamber design.

and longitudinally of the rotor. Thus it is apparent that lubricantunder pressure may be introduced at one end of the rotor and removedfrom the other end. Felt packing 44 disposed within circumferentialgroove 45 in bearing housing 28 creates a seal between journal 2'? andbearing housing 28, thereby preventing escape of lubricant. Anyconventional means such as pump 47 may be employed to supply oil underpressure to the lubrication system.

As best seen in Fig. 2, lubricant is conveyed from holes 36 into slots 6and holes 9 through holes 40. Holes ill are drilled perpendicular toslots 6 through holes 36 from the periphery of the rotor. The ends ofholes 40 are sealed in a similar manner to the ends of holes 26, 34 byplug 41 having a relatively long shank to prevent air pockets. Plugsmust be cut oil flush with the rotor after the lubrication passages aredrilled.

Needle valves 42 are provided in holes adjacent slots 6 to provide apredeterminate amount of lubricant to the vanes 7. To providelubrication between the vanes and the inner wall of the housing 65,holes 43 are provided through vanes 7 drilled radially of the rotor.Thus lubricant in holes '9 and slots 6 will be pumped radially outwardlyagainst the inner wall of the housing by reciprocations of vanes 7caused by the variations in radius of the inner wall of the housing. Itshould be noted that lubrication between vane 7 and wall 65 is suppliedin greatest quantity when vane 7 leaves the concentric sec tion of theinner wall and engages the juncture 25. at which point the need forlubrication is greatest because of the increased pressure between thevane and the wall.

A continuous air supply to the engine is effected through inlet openingin the housing 2. Pipe 51 containing air under pressure is connected tothe housing 2 by means of flange 52 rigidly secured to pipe 51 andconnected to the housing in registration with opening 50 by means ofbolts 53. The air pressure may be obtained from any conventional blower54 which may be conveniently mounted on top of housing 2 by means ofbolts 55, and driven by any suitable source.

Fuel is injected into the housing through hole 56 which is preferablylocated where the clearance between the rotor and the inner wall of thehousing is a minimum. Fuel may be supplied by any conventional pump 63through pipe 57 which is secured to the housing by means of flange 58and bolts 59.

Spark plug 69 is threadedly mounted in hole 61 in the side of thehousing and is preferably positioned where the inner wall of the housingcurves radially inwardly as at one of junctures 25.

An exhaust port 62 in the housing wall conducts the exploded gases tothe atmosphere. Exhaust pipe 63 is secured to housing 2 in registrationwith hole 62 by means of flange 64 and bolts 65.

Assuming counter-clockwise rotation in Fig. 2, fresh air is forced intothe engine through inlet opening 50 which is preferably located withrespect to exhaust port 62 so that exploded gases are blown out throughport .62 during a short period of the rotation of rotor 4. Thus theconventional scavenging cycle of a two cycle engine is simulated.

Fresh air confined between two vanes will be compressed upon continuedcounter-clockwise rotation due to the decreasing volume of the spacebetween vanes.

Thus it is apparent that the four vanes shown in the preferred formdivide the space between the rotor 4 and the inside wall of the housinginto four combustion chambers. The number of vanes is of course notcritical and may be any number depending on the size of the engine andthe power to be developed.

Fuel may be injected into each combustion chamber prior to firing at anytime consistent with good combus- The location of the fuel injection ispreferably as shown in Fig. 2 to obtain maximum vaporization of thefuel. Spark plug tires when the leading vane of a combustion chamber isat point 23' of the major concentric portion 23 of the housing 2. Itshould be noted that when an explosion takes place within a combustionchamber, the leading vane (assuming counter-clockwise rotation) does notmove radially thereafter until the pressure attending the explosion isdissipated. Thus wear on the vanes is minimized.

The engine may be cooled by circulating water around the outer wall ofthe housing within a water jacket made of sheet metal or the like andbolted to the housing by bolts 71 as shown in Figs. 1 and 2.

it will be apparent that the invention herein described may with slightmodification be converted into a diesel engine by eliminating the sparkplug, relocating the fuel injection opening and increasing thecompression ratio. in order to develop high compression ratios of sayten or twelve to one it has been found necessary to make the clearancebetween the rotor and the inside of thehousing very slight, say .082inch and also to provide slots 75 in the inner wall of the housing, andcorresponding projections 76 on'the radially outwardly projecting edgeof the vanes 7 as may be seen in Figs. 5, 6 which figures disclose amodified form of the invention. Those elements in Figs. 5, 6 that areidentical with the elements shown and described in the other views willbear the same numbers. Since the clearance between the rotor and theinner wall of the housing is so slight, substantially all of the fluidcarried past the inner wall of the housing at the short concentricportion of said wall designated 24 must pass through said slots. Thusthe frictional force resisting the flow of fluid past the inner wall ofhousing 65 is diminished by decreasing the periphery of the area throughwhich the fluid flows.

The engine develops its power in all forms of the invention by virtue ofthe difference in area subjected to pressure between the leading vaneand the trailing vane of any combustion chamber.

Various modifications may be made of the invention disclosed withoutdeparting from the spirit of my invention. For example, fuel may bemixed with the fresh air instead of injecting the fuel separately andthe spark plug may be omitted as explained above.

I claim:

1. In a rotary internal combustion engine, a housing having coaxialcylindrical inner sides in two sections of different radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumferentially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejunctures between the adjacent ends of said sections being graduallycurved to provide a gradual merging of said section at said junctures, arotor supported within said housing for rotation about the common axisof said sections, spaced vanes carried by said rotor and extendingradially therefrom into sliding engagement with said sections andmovable radially relative to said axis for passing over said juncturesin engagement therewith, an inlet in said housing for supplying airunder pressure to the space between said rotor and said inner sides ofsaid housing, and an outlet for exhausting the products of combustionfrom said space, said inlet and outlet being spaced apart in said othersection a distance relative to the spacing of said vanes to permit saidinlet to comm-unicate with said outlet through said space for aninterval during said rotation for scavenging .said products from saidspace.

2. In a rotary internal combustion engine, a housing having coaxialcylindrical inner sides in two sections of difierent radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumfereutially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejunctures between the adjacent ends of said sections being graduallycurved to provide a gradual merging of said sections at said junctures,a rotor supported within said housing for rotation about the common axisof said sections, spaced vanes carried by said rotor and extendingradially therefrom into sliding engagement with said sections andmovable radially relative to said axis for passing over said juncturesin engagement therewith, an inlet in said housing for supplying airunder pressure to the space between said rotor and said inner sides ofsaid housing, and an outlet for exhausting the products of combustionfrom said space, said inlet and outlet being spaced apart in said othersection a distance relative to the spacing of said vanes to permit saidinlet to communicate with said outlet through said space for an intervalduring said rotation for scavenging said products from said space, saidinlet being spaced from the adjacent juncture of said sections adistance substantially equal to the spacing between said vanes at saidinner sides, and said rotor being rotated in a direction for carrying acharge of air from said inlet toward said last mentioned juncture forcompressing such charge adjacent said short section.

3. In a rotary internal combustion engine, a housing having coaxialcylindrical inner sides in two sections of difi'erent radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumferentially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejunctures between the adjacent ends of said sections being graduallycurved to provide a gradual merging of said sections at said junctures,a rotor supported within said housing for rotation about the common axisof said sections, spaced vanes carried by said rotor and extendingradially therefrom into sliding engagement with said sections andmovable radially relative to said axis for passing over said juncturesin engagement therewith, an inlet in said housing for supplying airunder pressure to the space between said rotor and said inner sides ofsaid housing, and an outlet for exhausting the products of combustionfrom said space, said inlet and outlet being spaced apart in said othersections a distance relative to the spacing of said vanes to permit saidinlet to communicate with said outlet through said space for an intervalduring said rotation of scavenging said products from said space, saidinlet being spaced from the adjacent juncture of said sections adistance substantially equal to the spacing between said vanes at saidinner sides, and said rotor being rotated in a direction for carrying acharge of air from said inlet toward said last-mentioned juncture forcompressing such charge adjacent said short section and means forinjecting fuel into said space at said short section.

4. In a rotary internal combustion engine, a housing having coaxialcylindrical inner sides in two sections of different radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumferentially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejunctures between the adjacent ends of said sections being graduallycurved to provide a gradual merging of said sections at said junctures,a rotor supported within said housing for rotation about the common axisof said sections, spaced vanes carried by said rotor and extendingradially therefrom into sliding engagement with said sections andmovable radially relative to said axis for passing over said juncturesin engagement therewith, a firing chamber adjacent one of said juncturesdefined by a pair of adjacent vanes and said rotor and said inner sides,a spark plug positioned in said chamber for exploding a combustible gasin the same, said spark plug being adapted to be fired when the leadingvane relative to the direction of rotation of said pair is engaging saidother section and the trailing vane of said pair is engaging said shortsection whereby said leading vane will traverse said other sectionbetween said junctures after said explosion without undergoing radialmovement relative to said axis.

5. In a rotary internal combustion engine, a housing having coaxialcylindrical inner sides in two sections of difierent radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumferentially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejunctures between the adjacent ends of said sections being graduallycurved to provide a gradual merging of said sections at said junctures,a rotor supported within said housing for rotation about the common axisof said sections, spaced vanes carried by said rotor and extendingradially therefrom into sliding engagement with said sections andmovable radially relative to said axis for passing over said juncturesin engagement therewith, a firing chamber adjacent one of said juncturesdefined by a pair of adjacent vanes and said rotor and said inner sides,a spark plug positioned in said chamber for exploding a combustible gasin the same, said spark plug being adapted to be fired when the leadingvane relative to the direction of rotation of said pair is engaging saidother section and the trailing vane of said pair is engaging said shortsection whereby said leading vane will traverse said other sectionbetween said junctures after said explosion without undergoing radialmovement relative to said axis, an outlet for exhausting the products ofcombustion from said space and an inlet for supplying air under pressureto said space, said outlet being spaced from said one juncture adistance substantially equal to the spacing between vanes at said sides,and said inlet being spaced from said outlet a distance less than thespacing between said vanes for scavenging said products through saidoutlet by the pressure of 'said air.

6. In a rotary internal combustion engine, a housing having coaxialcylindrical inner sides in two sections of different radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumferentially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejunctures between the adjacent ends of said section being graduallycurved to provide a gradual merging of said sections at said junctures,a rotor supported within said housing for rotation about the common axisof said sections, spaced vanes carried by said rotor and extendingradially therefrom into sliding engagement with said sections andmovable radially relative to said axis for passing over said juncturesin engagement therewith, a firing chamber adjacent one of said juncturesdefined by a pair of adjacent vanes and said rotor and said inner sides,a spark plug positioned in said chamber for exploding a combustible gasin the same, said spark plug being adapted to be fired when the leadingvane relative to the direction of rotation of said pair is engaging saidother section and the trailing vane of said pair is engaging said shortsection, whereby said leading vane will traverse said other sectionbetween said junctures after said explosion without undergoing radialmovement relative to said axis, an outlet for exhausting the products ofcombustion from said-space and an inlet for supplying air under pressureto said space, said outlet being spaced from said one juncture adistance substantially equal to the spacing between vanes at said sidesand said inlet being spaced from said outlet a distance less than thespacing between said vanes for scavenging said products through saidoutlet by the pressure of said air and means for injecting fuel throughsaid short section under pressure into said firing chamber.

7. In a rotary internal combustion engine, a housing having coaxialcylindrical inner sides in two sections of different radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumferentially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejunctures between the adjacent ends of said sections being graduallycurved to provide a gradual merging of said sections at said junctures,a rotor supported within said housing for rotation about the common wisof said sections. spaced vanes carried by said rotor and extendingradially therefrom into sliding engagement with said sections andmovable radially relative to said axis for passing over said juncturesin engagement therewith, an inlet in said housing for supplying airunder pressure to the space between said rotor and said inner sides ofsaid housing, and an outlet for exhausting the products of combustionfrom said space, said inlet and outlet being spaced apart in said othersection a. distance relative to the spacing of said vanes to permit saidinlet to communicate with said outlet through said space for an intervalduring said rotation for scavenging said products from said space, saidinner sides having a plurality of circumferentially extending parallelgrooves therein, said vanes having a plurality of extensionsintermediate their ends extending radially outwardly of the outer edgesof said vanes and slidable in said grooves.

8. In a rotary internal combustion engine, housin having coaxialcylindrical inner sides in two sections of different radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumferentially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejuncturcs between the adjacent ends of said sections being graduallycurved to provide a gradual merging.

of said sections at said junctures, a rotor supported within saidhousing for rotation about the common axis of said sections, spacedvanes carried by said rotor and extending radially therefrom intosliding engagement with said sections and movable radially relative tosaid axis for passing over said junctures in engagement therewith, aninlet for air and an outlet for exhaust gas communicating with theinside of said housing at spaced points therearound, said sides and saidrotor defining a continuous space surrounding the latter and dividedinto a plurality of chambers each extending between a pair of adjacentvanes, said rotor being spaced a relatively short distance from saidshort section, whereby a charge of gas in a chamber between a pair orvanes engaging said other section will be compressed upon movement ofsuch pair to a position with the leading vanes of said pair inengagement with said short section.

9. .In a rotary internal combustion engine, a housing having coaxialcylindrical inner sides in two sections of different radii, the sectionof smaller radius being relatively short with respect to the othersection in direction circumferentially of the same and disposed betweenthe ends of said other section, the inner sides of said housing at thejunctures between the adjacent ends of said sections being graduallycurved to provide a gradual merging of said sections at said junctures,a rotor supported within said housing for rotation about the common axisof said sections, spaced vanes carried by said rotor and extendingradially therefrom into sliding engagement with said sections andmovable radially relative to said axis for passing over said juncture inengagement therewith, an inlet for air and an outlet for exhaust gascommunicating with the inside of said housing at spaced pointstherearound, said sides and said rotor defining a continuous spacesurrounding the latter and divided into a plurality of chambers eachextending between a pair of adjacent vanes, said rotor being spaced arelatively short distance from said short section, whereby a charge ofgas in a chamber between a pair of vanes engaging said other sectionwill be compressed upon movement of such pair to a position with theleading vane of said pair in engagement with said short section, thecircumferential length of said short section being less than thedistance between adjacent vanes at said sides whereby air will be drivenin a relatively narrow stream at a relatively high velocity between saidrotor and said short section in the direction of rotation of said rotorupon movement of said pair from said last mentioned position to aposition with said leading vane in engagement with said other section,an inlet in said short section for introducing fuel into said stream.

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